Acoustic Elegance TD12 - which version?

[Defo]

How does the TD12X compare to TD12M in terms of sound quality in the midrange? When do they start beaming?

Reason I'm asking is because I want to switch out my JBL 2226H to something slightly smaller to integrate better with my room, in both size and sound.

Ive modeled them both in WinISD in an appropriate enclosure size of 75 liters, and I get the best results the TD12X, both in response, and box simplicity. The TD12M needs really large long ports to avoid vent noise, which is hard to do in such a small enclosure. On the other hand, the TD12M may integrate better with my compression driver..

Any thoughts?

[Norris Wilson]

Hi defo,

If you cannot obtain the information that you have requested here within. You might consider asking these questions on the Audio Kinesis forum here:

http://www.audiocircle.com/circles/i...hp?board=135.0

I know Duke LeJuene has been using the AE TD12 drivers for a while in his latest designs.

Also, Wayne Parham of Pi Speakers has a pair of the TD12S version on order. He is going to evaluate them with the idea to offer them in his Three Pi design as an upgrade if they are superior to the JBL 12" that he uses now.

You can ask Wayne about this on his forum at:

http://audioroundtable.com/PiSpeakers/

I hope you can find out what you seek.

It would be very much useful to many of us on the side lines considering the AE TD line of drivers.

Please keep us informed?

Good luck!

NW

[JoshK]

I think you are reasoning correctly. I've done similar modeling in unibox and get similar results. I have a pair of the TD12Ms and TD15Xs. The Xs are more midbasses and the M more midranges.

I am sure you can use either well, but if this is a 2way without subwoofers, then TD12X seems easier to work with. I don't know about the high end of the TD12X cause I haven't used it. I'd ask john j at aes.

what waveguide are you planning to use?

[John_E_Janowitz]

Both the TD12X and TD12M use the same cone profile. As a result they will start beaming at the same frequencies. This frequency is primarily determined by the diameter of the driver. The cone profile and addition of the phase plug can improve the off axis response some, but not a huge amount. The high frequency limit depends on how far off axis you need to go. I know some people who would only use a 12" driver to 500hz as they want very wide off axis response. Others have used the TD12's to 2KHz as they want a more narrow controlled pattern.

The difference between the TD12X and TD12M is going to be less in the upper response but more in the middle of their band. The foam surround on the TD12X gives it more excursion but the cloth surround on the TD12M is more well damped. Either can still work very well covering up to 2KHz. You can see Jeff Bagby's comments on the TD12H used in the new Salk Sound speaker in the following post.

http://www.htguide.com/forum/showpos...2&postcount=44

"I have to jump on John J.'s bandwagon here - the Lambda woofers he is making are very special drivers, capable of doing things that most drivers can not begin to touch. For example their ability to reach deep in the bass with a good Xmax, and at the same time maintain extremely low non-linear distortion values into the midrange are pretty much unprecedented. The 12" I used had the Le of 4" driver and had a flat response on-axis to 2.5kHz. The Lambda will give you bass slam and a low distortion mid that can cross effectively to a dedicated midrange that you will not get with hardly any other woofer."

Regarding the port comparison, your port length determines the tuning frequency and then the length is determined in proportion to the vent area. The more air you need to move, the larger the vent area to keep vent velocity and noise down. This is all determined by the SPL levels you wish to achieve. Example, 110dB at 30hz requires about the same amount of port area for a given velocity whether you use the X or M.

I'd start by determining what your low end frequency goal is and what SPL levels you wish to achieve. Then we can work from there.

John

[Defo]

Planning on using the 18 sound XT1086 waveguide and possibly upgrading to Azura 550 or 340 later when I have the economics to.

John:

Regarding beaming, im thinking about trying ribbons, so it may be important to have the possibility to cross high. My spl level requirements is about 110 db. You are saying that the TD12M wont have any port issues degrading sound quality, compared to the TD12X? And that the response in the upper range is about the same? WinISD shows a lot higher vent velocity with the TD12M then the X version.

What about integration to a sub? I guess the TD12X is a tad better at this subject?

[doug20]

I will be following this thread.

I have TD12S still in boxes looking for waveguide designs. The XT1086 is on my list too!

I believe my TD12S plays pretty well up past 1500Hz from my tests so far. No measurements as of yet though!!

I have TD12S also in a three way with the Neopro5i/Ph1120 drivers (Active crossovers). I just want to try a 2-way next

any reason you didnt consider the TD12S?

[doug20]

More active crossover info if you are interested in the 3-way active settings. I cross the Neopro5i over at 2K and the PHL1120 handles 400Hz to 2K.

[johngalt47]

How is the TD12H different from the others?

[dlneubec]

The TD12H is designed to go lower, with no need for a sub for music, at the expense of some sensitivity (it's about 93db, IIRC). I'm using it in a ported 52L cabinet with an F3 of about 35-36hz. It is the best bass driver I've used or heard.

In my case, I cross it to a B&C 6md38 at 460hz, between second and third order, but it measures flat to well over 2khz.

[johngalt47]

Is your box sealed or ported?